Human forced expiratory noise. Origin, apparatus and possible diagnostic applications.

Forced expiratory (FE) noise is a powerful bioacoustic signal containing information on human lung biomechanics. FE noise is attributed to a broadband part and narrowband components-forced expiratory wheezes (FEWs). FE respiratory noise is composed by acoustic and hydrodynamic mechanisms.

An attempt at hydroacoustic localization of an open-circuit scuba diver.

Passive acoustic monitoring of scuba divers is a promising way to ensure the safety of recreational divers and prevent waterside intrusion by terrorists. It is shown experimentally that the low-frequency underwater respiratory-associated noise of an open-circuit scuba diver can be used successfully to monitor the respiratory rate at distances of up to 100 m. Respiratory-associated noise in the frequency band of 30-1200 Hz provides the possibility of localizing an open-circuit scuba diver in a noisy shallow-water area by using two pairs of hydrophones at distances of up to 220 m and with a predominant discrepancy of no more than 10 m in comparison with Global Positioning System data.

A Technique of Forced Expiratory Noise Time Evaluation Provides Distinguishing Human Pulmonary Ventilation Dynamics During Long-Term Head-Down and Head-Up Tilt Bed Rest Tests Simulating Micro and Lunar Gravity.

Estimating the effect of microgravity/hypogravity on pulmonary ventilation function remains topical. Recently developed acoustic techniques based on the evaluation of the forced expiratory noise time (FETa) were hypothesized to be a promising tool for this aim. The aim of the protocol is to study the effect of two different modalities of bed rest space simulations (microgravity and lunar gravity) on FETa and spirometric indices.

Measurement and estimation of human forced expiratory noise parameters using a microphone with a stethoscope head and a lapel microphone.

Objective: The time signature of tracheal noise in the 200-2000 Hz frequency band recorded during a forced expiratory manoeuvre (FET) is a promising tool for diagnosis of bronchial obstructions. FET is typically registered using a microphone with a stethoscope head placed on the neck over the trachea (stethoscope sensor). We studied basic time and spectral parameters of forced expiratory tracheal noises with a microphone placed near the mouth (lapel microphone, outside the flow of exhaled air) and compared these with measurements via stethoscope sensor, with the aim of providing patient home monitoring via standard personal computer facilities.

[Characteristics of flow standardized inspiratory lung sounds in healthy].

Objectification of respiratory sounds, recorded on chest surface, is important to assess human broncho-pulmonary system. The aim is to detail the objective characteristics of basic inspiratory sounds. The study involved 36 healthy men aged 19 to 80 years.